Reading about the Hill Sphere I notice that "the region of stability for retrograde orbits at a large distance from the primary, is larger than the region for prograde orbits at a large distance from ...

I could not find anywhere how long does it take for the earth to rotate around the center of mass of the earth moon system, which is located inside the earth but off-center. And does this motion have ...

I read this Phys.SE thread which is similar
Why are L4 and L5 lagrangian points stable?
but I did not want to necro that thread. It seems that most discussions of a three body problem are presented ...

If we imagine two suns of equal mass, and a small object in their combined center of gravity, which is not moving, it will stay there forever.
If the object is displaced a little bit towards one of ...

I have a question that I believe is relatively easy to answer, I am working on an $N$-body simulation of a fictional star system and am having trouble finding the velocity of moons so that they will ...

where did the rotational energy and angular momentum go?
Some claim that the angular momentum went to the Moon. Astronauts put a corner reflecting mirror on the moon and reflected a Laser and timed ...

Einstein famously explained the anomalous precession of Mercury by showing that in general relativity elliptic orbits precess even in the 2-body problem. But apparently in the early days of quantum ...

I'm writing a program that simulates Newton's law of universal gravitation by simply calculating the force and applying it on the objects. The simulation works very well, but now I want to simulate ...

Inspired by last week's solar eclipse, I'm wondering under what conditions one can see a total solar eclipse from the ISS. How often does it happen? I guess it doesn't last very long because of the ...

I need a free open source planetary orbit simulator software that should be able to calculate orbit stability for a couple simple planetary systems.
Basically, I need to calculate orbit durations for ...

From $$m\boldsymbol{\ddot{r}}=\boldsymbol{\hat{r}} f(r)$$ I can get
$$r''-r \theta '^2=-\frac{k}{m r^2}$$
$$2 r' \theta '+r \theta ''=0$$
Now it seems that all the books tells me the method to solve ...

If I may ask: How can the orbits of binary pulsar stars, with similar mass, be calculated from Kepler's laws? Considering that both large central masses must be located at their mutual foci. Also, how ...

I've assumed since the translational speed of the moon along its orbit undergoes the same boosts and reductions over its orbital course, the time between the apogee and the pedigee (and respectively, ...

I was wondering how precise the location of an object in a Lagrange point needs to be to maintain stability, since it seems that several natural objects (asteroids) exists together in some of these ...

How does one prove that an orbit of a satellite around a planet of significantly greater mass than the satellite is a conic section (i.e. an ellipse, circle, hyperbola, or parabola)?
Also, there is ...

A thought just came to me, and I want to comfirm it here:
If we figured out a way to harvest the energy from the orbit of the Moon, would that be perpetual?
The Moon has been orbiting the earth for ...

Suppose a physically realistic object of nontrivial size (such as a star) free-falls past a black hole. The center-of-mass trajectory for the object is hyperbolic and (therefore) completely outside ...

I know that three-body problem in celestial mechanics can't be solved analytically in general. But suppose that the 3rd body is much smaller than the others, so it does not perturb their orbits. This ...

What is the ultimate "goal" of two particles in a gravitational field?
Will the particles eventually occupy the same point at the same time if nothing stops them?
What stops them from achieving the ...

Why do Lagrange points L4 and L5 exist at all?
Consider the mass of Jupiter equals 320 Earth masses, and distance from Lagrange point to Jupiter is about 4-6 A.U. We get that the gravity of Jupiter ...

I read recently that the galactic "flatness" of the Milky Way is due to the rotation of the galaxy combined with a vast stretch of time.
Yet, I also read where 1) the Milky Way rotates once every 225 ...